Study on RuO₂/SnO₂: Novel and Active Catalysts for CO and CH₄ Oxidation

RuO 2 /SnO 2 catalysts with 2, 5 and 10 % Ru loadings were prepared with calcined and uncalcined SnO 2 supports by the impregnation method. The catalysts were evaluated for CO and CH 4 oxidation and characterised by N 2 ‐BET, XRD, hydrogen temperature programmed reduction (H 2 ‐TPR), energy‐dispersive X‐ray spectroscopy scanning electron microscopy (EDS‐SEM) and thermogravimetric analysis differential scanning calorimetry (TGA‐DSC). Owing to the synergetic effect between RuO 2 and SnO 2 , all RuO 2 /SnO 2 catalysts are found to be much more active than pure SnO 2 and RuO 2 /Al 2 O 3 for both CO and CH 4 oxidation. For RuO 2 supported on uncalcined SnO 2 , H 2 ‐TPR and TGA‐DSC analysis revealed the formation of a new, less active compound between Sn and Ru that consumed active SnO 2 and RuO 2 , and could be detrimental to the synergism between RuO 2 and SnO 2 , and thus the activity of RuO 2 /SnO 2 catalytic system. As a consequence, it is much less active than RuO 2 supported on calcined SnO 2 . RuO 2 /SnO 2 catalysts are also very stable in the presence of water vapour, which gives them potential for application in after‐treatment processes.